bio 2 - lecture #5 (midterm #2 content)

what is redox chemistry?

transfer of electrons

electron movement

release energy that will be harvested

reduction

gain of hydrogen + electrons

oxidation

loss of hydrogen + electrons

electron acceptor

what undergoes reduction

electron donor

what undergoes oxidation

reduced state

• has more electrons than oxidized state

• is a better electron donor

oxidizing state

• less electrons than reduced state

• is a better electron acceptor

oxidizing agent/compounds

• causes oxidation by gaining electrons and undergoes reduction

• good electron acceptors and bad electron donors

reducing agent/compunds

• causes reduction by donating electrons and undergoes oxidation

• good electron donors and bad electron acceptors

reduced substances with lower E^°’

• will transfer electrons to oxidized substances with higher E^°’ spontaneously (favorable)

reduced substances with higher E^°’

• will transfer electrons to oxidized substances with lower E^°’ non-spontaneously (unfavorable)

E^°’

• represents standard reduction potential

• measured in volts (V)

• measures how well reduced compounds donate electrons and oxidized compounds accept electrons

equation for difference of E^°’

E^°’ electron acceptor - E^°’ electron donor

what happens when you know ΔE^°’?

you can calculate the difference in free energy (ΔG^°’)

what happens if a reaction has a positive ΔE^°’?

• ΔG^°' will be negative, which is favorable and spontaneous

what happens if a reaction has a negative ΔE^°’?

• ΔG^°' will be positive, which is unfavorable and non-spontaneous